Cosmetic and skin care formulations involve the use of oils from animals, natural plants and organic synthesis to build a carrier for active ingredients and to set up a barrier against environmental influences such as dirt, chemicals and microorganisms and against the loss of endogenous substances such as natural fats and water. The oils could often cause an unpleasant oily, greasy feel on the skin. Consequently, a skilled cosmetic formulator often chooses to add powders of, for example, nylon, polymethylmethacrylate, polyurethane, silica and polymethylsilsesquioxane into cosmetic formulations to reduce the undesirable skin feel. While these powders provide a reasonable skin sensory and oil control benefit, they suffer the disadvantage of high cost and low efficacy. Their sensory feel is not obvious when they are used in liquid formulations at a level of about 10% or lower. But if their concentration in the formula is too high these powders lead to an undesirable texture and appearance.
Recently, silicone elastomer powder has found increased use in cosmetic formulations because it imparts a very smooth feel and absorbs a large amount of oil at a relative low concentration, resulting in a matte appearance. The preparation and cosmetic applications of silicone elastomer have been disclosed in Japanese Pat. JP 1190757, issued to Toru et al.; U.S. Pat. No. 4,987,169, issued to Kuwata et al.; U.S. Pat. No. 5,266,321, issued to Shukuzaki et al.; U.S. Pat. No. 5,919,468, issued to Bara; and U.S. Pat. No. 6,524,598, issued to Sunkel et al. While the silicone elastomer has advanced the approach to battle the oily, greasy feel, it still suffers from an unsatisfactory performance. A wet, draggy feel is often observed in the initial application to the skin when a high viscosity silicone fluid or a vegetable oil is used in formulations.
It remains desirable to further improve the sensory feel of the delivery system for cosmetic applications. It would be especially desirable to have new systems carrying modified silicone powder to provide an improved dry-smooth feel.